With regard to the original post, the Maata jersey was prepared for him, but he unexpectedly made the Penguins so he never wore it. The jersey should have been sold as game issued, not game worn. However, the buyer probably should have been aware that Maata didn't play for the Knights that season since he worked for the team.
As for Sefton, he was traded during training camp, so again a jersey was prepared for him but never used.
I've been told that the Tierney is actually game used but didn't have a lot of wear because it's the black alternate and only used in 6 games that season. For whatever reason, the Knights attached the Memorial Cup patch to all of the jerseys, even if they won't be used during the tournament.